Anchor iron



Dec. 3, 1940. .w BOWMAN, JR 2,223,596

ANCHOR IRON v Filed Dec. 24, 1938 flAk/LKAQQ .6: flan MAN J2.

INVENTOR flrTo zvEr Patented Dec. 3, 1940 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to improvements in timber anchors or anti-checking anchor irons, i. e., devices which generally are intended to be driven edgewise into the ends of cross ties and other pieces of timber for the purpose of retarding and preventing spike splits, vertical checks, season checks, and other splits or irregularities in the wood.

Heretofore, various forms of anchor irons have been proposed and used, the most common being the Z, S, and C forms. These irons have been fashioned from either plain or corrugated material with one of their longitudinal edges singly or doubly beveled to facilitate their intrusion into the wood. The holding power of any such iron is measured by the force required to withdraw it from a cross'tie or other piece of wood into which it has been driven. It is desirable to maximize the holding power since it is a measure of the ability of the iron to resist extrusion from the wood due to the forces set up by vibration, expansion, contraction, etc. to which it may be subjected during use.

The principal object of this invention is to increase the holding power of anchor irons without deleteriously affecting their other features.

A further object is to provide a novel form of iron having .a unique shape which substantially increases its holding power.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a perspective view of an anchor iron constructed in accordance with my invention;

Figure 2 is an end elevation of a cross-tie fragment into which the iron is embedded; and

Figure 3 is a section taken transversely through the embedded iron.

While the invention may be applied to any of the anchor irons heretofore used or proposed, it is illustrated as applied to an iron having the shape of a Hindu bow. Such iron comprises a metal strap having an arched-back portion l, and, at opposite ends thereof, re-entrantly turned end portions 2 which are corrugated as indicated at 3. The longitudinal penetrating edge 4 of the iron is sharpened in. any customary Way as by the double bevel shown, while the opposed longitudinal lagging edge preferably remains flat.

Now in accordance with my invention, the iron is provided between its penetrating and lagging edges with a longitudinally extending molding 5 for the purpose of increasing the holding power of the iron. The molding does not operate to produce an immediate increase in holding power, i. e., one which is effective from the moment the iron is driven into the wood. After the iron has been embedded, however, the molding affords a raised surface or shoulder against which the fibers of the wood, will, in time, contract to interlock the iron in its embedded position and thus increase the force necessary to withdraw it. In that way, however, the holding power of the iron may be said to be increased.

While the molding 5 used may be of any suitable shape, I prefer the ratchet or spur type of molding shown, which presents a beveled surface on its penetrating side and a sharp or abrupt holding surface on its lagging or interlocking side. Although only one molding is necessary, I refer to provide a molding on each major face of the strap forming the iron. Such moldings may be placed in opposed relation or in the staggered arrangement shown.

In the aplication of this device, the anchor iron is positioned in desired relation to the particular split or check condition involved and then driven into the wood in the customary manner to a depth such that its lagging edge is flush with the exposed end face of the wood. In this position, the moldings will be embedded some distance beneath the end face. Thereafter, as the wood seasons, the wood fibers contract and, in doing so, tend to cling more and more tightly around the moldings thus correspondingly increasing the holding power of the iron. I have found that substantial increases in holding power can be normally expected within relatively short periods of time after the irons are first embedded. The holding-power tests made on this type of iron indicate that the moldings ultimately increase the holding power from as much as 75% to depending upon the greenness of the timber, it being understood, of course, that the greener timbers will produce the greater contractions during seasoning; hence the greater increases in holding powers.

Having described my invention, I claim:

1. A timber anchor iron comprising: a longitudinal anchor iron body having longitudinal penetrating and lagging edges; and a ratchet or spur type holding member integrally formed on said body between said edges, said member presenting a beveled surface on the penetrating side and a sharp holding surface on the lagging side.

2. A timber anchor iron comprising: a longitudinal anchor iron body having longitudinal penetrating and lagging edges; and a ratchet or spur type molding on and extending longitudinally along said body between said edges, said ing longitudinal penetrating and lagging edges; molding presenting a beveled surface on its peneand a ratchet type of molding on and. extending trating side and a sharp holding surface on its longitudinally along each face of said strap belagging side. tween said edges, said moldings being arranged 3. A timber anchor iron comprising: an anin staggered relation relatively to each other. 5 chor iron body in the form of a metal strap hav- WALKER H. BOWMAN J R. 

